Switches are used in many applications to control the flow of electrical energy. The switches can be used to redirect electrical energy from one circuit to another, and can be used to stop the flow of electrical energy through a circuit. In both cases the circuits become de-energized, that is without a voltage. One particular type of switch is a circuit breaker which cuts off the flow of electrical energy when the flow of electrical energy through the switch exceeds a predetermined value. Many of these circuit breakers include a lever which is movable between an “On” position and an “Off” position.
Maintenance personnel often use a circuit breaker to cut the flow of electrical energy through a circuit when the circuit, or electrical components connected thereto, require maintenance. The circuit breaker, however, is often remote from the location requiring maintenance. Therefore, it is desirable to lock out the circuit breaker to prevent an individual from inadvertently energizing the circuit while maintenance is being performed.
Known circuit breaker lock out assemblies engage the circuit breaker lever to prevent unauthorized movement of the lever. Lockouts such as disclosed in U.S. Pat. Nos. 5,593,020; 5,794,760, and 5,900,600, include a lock arm cantilevered from a lock rail. The lock arm includes a head that engages or covers the circuit breaker lever to prevent unauthorized movement of the lever. The lock out devices as taught within the cited references, can easily be circumvented by lifting the cantilevered head away from the lever and thus disengaging the lever from the head. As a result, the lock out adequately serves to provide notice to an individual that movement of the lever is unauthorized, however, it is not always effective to prevent unauthorized lever movement.
Another disadvantage of the prior art cantilevered lock out device is the inability to lock out adjacent circuit breakers aligned along an axis perpendicular to the lock rail. Only one opening in the lock rail can be used to hold a cantilevered lock arm, and each lock arm can lock out only one circuit breaker. In addition, the prior art cantilevered lock out assemblies disclosed in the above referenced patents, are very complicated and use numerous parts that the present invention clearly eliminates.
Another type of an electrical lockout device is taught within U.S. Pat. No. 5,451,730 entitled “ELECTRICAL SAFETY APPARATUS” which substantially teaches an elongated insulated rod having an upper disconnect hook to engage a handle of a switch box. This apparatus is functional for its intended use but still has inherent disadvantages and drawbacks that the present invention recognizes, addresses and resolves in a manner not heretofore taught. For example, this type of lockout apparatus does not provide a suitable locking mechanism such as a typical pad lock, and due to strict regulations it is unlikely this apparatus would be allowed or approved. The locking mechanism is simply a curved bar which is held in a locked position by a tension spring. Thus, use of a spring is not effective as springs tend to easily wear out and the tension is variable which is most unfortunate as this results in an inefficient locking mechanism.
One of the most important drawbacks of the known prior art is the fact that the workman must be within arms reach of the electrical disconnect box so as to be able to shut the switch off and then attach a pad lock. This is very important as “Osha” regulations are very clear and precisely state that a pad lock or the like must be incorporated for a safe and secure lockout. This can be very difficult because most industrial facilities have pallets, crates, materials and other obstacles between the affected machines. Thus, such items must be removed and/or re-positioned so as to allow the workman access to the electrical disconnect box. This not only results in increased cost and loss of valuable time but is also dangerous for the workman as they must further climb onto a step ladder or the like to obtain proper height for attaching the pad lock.
It is therefore contended that a need exists for a new and improved type of lockout device that may be used for disconnecting overhead electrical switches and which eliminates the inherent drawbacks and disadvantages of the known prior art. It is further contended that such a lockout device should be durable, safe, easy to use and inexpensive to manufacture. It is also important to provide simple assembly and installation instructions, such as taught within the forthcoming specifications.